Calculating-machine.



S. E. MYERS.

CALCULATING MACHIN E.

APPLICATION FILED FEB- 10, 1912.

1,161,065. v A PatentedNov. 23, 191.5.

Fig.1!

WITNESSES: I/VVE/VTUR MM 2 i SEM 91ers.

' UNITED s'rATEs PATENT o i STELLA E. MYERS, OF KANSAS CITY, KANSAS CALCULATING-MACHINE.

To all whom it ma y concern: v

Be it known that I, STELLA MYERs,a

citizen of the United States,-residing at Kansas City, in the county of VVyandotte Specification of Letters Patent.

and State of Kansas, have invented certainnew and useful Improvements in Calcu-.

lating-Machines; and I do declare the following to be a full, clear, and exact description of the invention, such as 'will enable others skilled-in the art towhich it appertains to make and use the same, reference being had' to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification. x p My invention relates to improvements in calculating machines, and more particularly to a device of thattype which is adapted for school use, and can ,be readily understood and operated by children in kindergartens and primary schools.

More particularly, my device consists of two concentric disks, one of whichiis superimposed on the other, and each of which is provided on its upper face with fractional markingsarrangedon a plurality of con centric, multicolored rings. rings are provided forthe reason that they form distinctive divisions for containing the The colored tions is printed. A circumferential section of the upper disk, and the exposed rim of the outer disk have each a plurality of conrmon.

Patented Nov. 23, 191-5.

Application filed February 10, 1912. Serial No. 676,755.

centric rings of distinctive colors, the rings in the upper disk 3 corresponding with the rings in the lower disk in number, color and order, although I prefer to reverse the 'arrangement of the rings in the separate disks,

so that the outside ring of the upper disk corresponds in color with the inside ring of the lower disk, and is in close proximity thereto.

The drawing shows each disk, provided with seven distinctively colored rings, and

for convenience I have numbered the rings on the base disk from 5 to 11 inclusive, and

those on the upper disk from 5 to 11' inclusive, the rings of like color bearing like reference numerals.

Extending across the rings of both disks are the blank columns 1212", each of which is preferably provided with a star 1313f or the like, to indicate a starting position, and

also extending across saidrings are the ra-- "dial' lines 14-14 which divide the rings fractions) and are pleasing to the eyes ofchildren, thereby stimulating interest I in operating the calculator, and assisting to their color. Fig. II is a view on the line II-II of Fig, I.

develop the mathematical faculties.

. In the drawings forming a. part of this specification, wherein the preferred form of my device is illustrated, and wherein like reference numerals refer to like parts throughout the several vi'ewsz' Figure I is a {top plan view of a calculating device con-v structed according to .my invention, two

rings on each disk being'shaded to indicate in cross section Referring more in detail to the "parts The mechanical elements of the device comprise a base diskll having a spindle 2;-and

. an upper disk 3, which is vrevoluble on'said spindle? The disks 1 and 3 may be con-f structed. of heavycard board, aluminum, or

any 'suitableifnaterial of suflicient rigidity to The upper,.

into separate sections wa, b-b.' etc. The number of divisions into which the disks are divided-is governed by the size of' the denominator of the fraction of least value to be used as, in the present device, the fraction of least value is one twenty-fourth, the disk is divided-into twenty-four sections. It is apparent, however, that the'number of sections may be varied without affecting the invention. Y i 7 With a device as illustrated in the drawings, .2. e. one inwhich each disk is divided into twenty-four sections, the fraction of least valu'e1/2Lis printed on the inner upper disk. As both. rings are the same color, red,.for instance, both'section's are in .ring 5 of the under disk, in thezfirst section. to the right of the blank 12, and also in a ,like position on the outer ring 5" of the 2/24.is printed. As this. fraction is reducible,.the reduced form 1/12is printed on the'adjacentrings 6 of the respective I I disks, being the next outer ring-on the under 55, for instance, purple.

, It is apparent that respective inner and outer rings of each successive section contain a fraction having 24 as denominator, and a numerator that increases in arithmetical progression. It is also apparent that by reducing the fractions where possible every second section'will contain a fraction having 12 as a denominator and having numerators increasing in arithmetical progression. As the value of the fractions increases, the reduction maybe carried.out to fourths, thirds and halves, the various fractions in device is in the tenth section on the lower.

disk 'to the right of the starting column.

The same method is employed in sub first locate the fraction l/G on the lowerdisk I and then revolve the upper disk until the fraction 1/8 on the upper disk is opposite that position. The answer 1/24, will be in the section of the lower disk opposite the indicator 13.

It is apparent that by placing fractions having the same denominators on rings having the same colors, it is'much easier to find a fraction on one of the disks corresponding withvthat located on the other disk.

each section differing inaform but not im With a device of this character, children value, and the different forms being printed in like colored rings on the separate disks.

Presuming the disks to be assembled and marked as described, two fractions may be added in the following manner :If to 1/6 we wish to add 1/4, we locate the fraction 1/6 on the under disk, then turn the upper disk until the indicator 13 is opposite that fraction. V e then locate the fraction 1/4 on the-upper disk, and the sum is found in the radial division 5 on the lower disk, which is v the division opposite the 1/6 'on the upper disk, the answer being any of the fractions in said division, although the outer fracin its reduced form. This result may be checked by reducing the fractions 1/6 and tion should. be stated, as that is the result 1/4 to twenty-fourths and checking ofi the number of spaces on the under disk indicated by the numerator of the sum, as 1/6 equals 4/24, and 1/4- equals 6/24; the sum is 10/24. The result indicated by the soon learn to recognize and distinguish the different colors, and can easily manipulate the disks, thereby acquiring mathematical aptitude more readily than under purely mental systems. Having thus described my invention, what I claim as new therein and desire to secure by Letters-Patent is 1 A calculating devicecomprising concentric disks each having a plurality of concentric rings divided radially into a primary and succeeding groups, all of the rings in succeeding groups bearing fractional markings of the same value and of a value greater than the fractional markings in a preceding group.

STELLA E. MYERS.

NVitnesses:

JOHN F. WADE, ARTHUR N. CAPS. 

